The present disclosure relates to branched fluorinated photopolymers. Such photopolymers are particularly useful in organic electronic and bioelectronic devices.
Photo-patternable polymeric compositions have many possible commercial applications. They can be used as photoresists, dielectrics, insulators, semiconductors, encapsulants, inert overcoats, water or oil repellent layers, light blocking or emitting layers, paints, printing inks and the like. Certain photo-patternable polymeric compositions are of particular use in the fabrication of organic electronic devices, including bioelectronic devices.
Organic electronic devices may offer certain performance and price advantages relative to conventional inorganic-based devices. As such, there has been much commercial interest in the use of organic materials in electronic device fabrication. Specifically, organic materials such as conductive polymers can be used to manufacture devices that have reduced weight and drastically greater mechanical flexibility compared to conventional electronic devices based on metals and silicon. Further, devices based on organic materials can be significantly less damaging to the environment than devices made with inorganic materials, since organic materials do not require toxic metals and can ideally be fabricated using relatively benign solvents and methods of manufacture. Thus, in light of these superior weight and mechanical properties, and particularly in light of the lowered environmental impact in fabrication and disposal, electronic devices based on organic materials are expected to be often less expensive than devices based on conventional inorganic materials.
One problem facing bioelectronic and organic electronic devices is that the materials and patterning processes used for conventional inorganic electronics are often not compatible with biological and chemical electronic materials. Thus, new materials and processes are needed.
For example, although the use of photoresists is routine in the patterning of traditional electronic devices based on inorganic materials, photolithographic patterning has been difficult when applied to bioelectronic or organic electronic materials. Specifically, bioelectronic and organic electronic materials are often much less resistant to the solvents that are used for conventional photolithography, with the result that conventional lithographic solvents and processes tend to degrade organic electronics. Although there have been various attempts to overcome these problems, e.g., by ink-jet printing or shadow mask deposition, these alternative methods do not produce the same results as would be obtained with successful photolithography. Neither ink-jet printing nor shadow mask deposition can generally achieve the fine pattern resolutions that can be obtained by conventional lithography.
U.S. Pat. No. 8,846,301 discloses a useful method for patterning organic electronic materials by an “orthogonal” process that uses fluorinated solvents and fluorinated photoresists. The fluorinated solvents were found to have very low interaction with organic electronic materials. WO 2012/148884 discloses additional fluorinated material sets for orthogonal processing. Although the orthogonal process has made good progress, the disclosed systems have yet to be commercially adopted. Further improvements in system performance and cost are desired.